When the request is completed, all controls are copied to the request object. However, when VIDIOC_G_EXT_CTRLS attempts to read control values from the request it will read the current value instead for any control reference that has a NULL ref->req pointer. But that's wrong: after completing the request *all* controls should have a non-NULL ref->req pointer since they are after all copied to the request. So set ref->req if it wasn't set already. Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx> Reported-by: Paul Kocialkowski <paul.kocialkowski@xxxxxxxxxxx> --- diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c index 2928c5e0a73d..93d33d1db4e8 100644 --- a/drivers/media/v4l2-core/v4l2-ctrls.c +++ b/drivers/media/v4l2-core/v4l2-ctrls.c @@ -4296,10 +4296,17 @@ void v4l2_ctrl_request_complete(struct media_request *req, continue; v4l2_ctrl_lock(ctrl); - if (ref->req) + if (ref->req) { ptr_to_ptr(ctrl, ref->req->p_req, ref->p_req); - else + } else { ptr_to_ptr(ctrl, ctrl->p_cur, ref->p_req); + /* + * Set ref->req to ensure that when userspace wants to + * obtain the controls of this request it will take + * this value and not the current value of the control. + */ + ref->req = ref; + } v4l2_ctrl_unlock(ctrl); }